Acacia from the Greek 'akakia' and derived from 'ake' or 'akis' meaning a sharp point or thorn and 'akazo' meaning to sharpen. Dioscorides, the Greek physician and botanist used the word in the 1st century AD for the Egyptian thorn tree, Acacia arabica. Rhigophylla from the Greek 'rhigelos' meaning rigid and 'phyllon' meaning a leaf, referring to the stiff unbending needle-like phyllodes.

Distribution:

Small occurrence on Eyre Peninsula and Murray region in open scrub associated with Eucalyptus socialis and E. gracilis, in hard alkaline red duplex or grey-brown calcareous loam soil. Also found in New South Wales.

Status:

Native. Locally common but rare in South Australia. Rare in New South Wales.

Plant description:

Rigid, prickly, spreading, intricately branched, dark green shrubs to 3 m high and usually wider than high. Branches terete, reddish-brown, which are slightly roughened and flaky at the base of stems and slightly pubescent with brown bark Leaves linear-lanceolate to 2.5 cm long and 2 mm wide; flat, rigid, sessile, divaricate, striate; glabrous with 2-3 prominent raised longitudinal veins and apex tapering into a reddish-brown pungent point. Flower-heads cylindrical to almost globular, bright yellow. Flowering between September and October.

Place the pods in a tray and leave to dry for 1-2 weeks or until the pods begin to split. Then rub the dried pods to dislodge the seeds. Use a sieve to separate any unwanted material. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place.

Seed viability:

From two collections, the seed viability was high, ranging from 95% to 100%.

Seed germination:

This species has physical dormancy that needs to be overcome for the seed to germinate (e.g. nicking or softening the seed coat).

Seeds stored:

Location

No. of seeds(weight grams)

Numberof plants

Datecollected

Collection numberCollection location

Datestored

% Viability

Storagetemperature

BGA MSB

9100 (42.81 g)9100 (42.81 g)

15-Dec-2005

PJA113Murray

1-Aug-2006

100%

-18°C

BGA MSB

2520 (12.4 g)2520 (12.4 g)

6-Dec-2005

TEE004Eyre Peninsula

1-Aug-2006

95%

-18°C

Location: BGA — the seeds are stored at the Adelaide Botanic Gardens, MSB — the seeds are stored at the Millennium Seed Bank, Kew, England.Number of plants: This is the number of plants from which the seeds were collected.Collection location: The Herbarium of South Australia's region name.% Viability: Percentage of filled healthy seeds determined by a cut test or x-ray.